Telegraphic transmitter



May zo, 1930.l F. MC'LROY 1,759,584

. TELEGRAPHIG TRANSMITTER Filed Aug. 7, 192:3v

NVENTOR ATTORNEY' Patented Mayy 2o, 1930 y l UNITED Asrii'rrss TELEGRAPIIIC IRANSMIIT'IIER` Application filed August 7,1928. Serial No. 297,953.`

. In telegraphic transmitters of the vibratory type now on the market,A it is customary to arrange the vibrating element so that it makes contact with a fixed member and then breaks the contactto transmit the dots of the telegraphic code. Dashesare made by individual manual movement of the key. I have found that a mechanism can be constructed by which bothdashes and dots can be transmitted in semi-automatic manner if the vibrating element is used to break va circuit which is closed by the same movement of the operating key which initiatesr the vibratory movement but is not closed -by the vibrator itself. My invention can best be understood by reference to the'accompanying drawings, in which I show a'plan view of an illustrative example of an apparatus embodying the invention with the electrical connections shown diagrammatically.

. In the drawing, designates the base, on which is mounted a bridge 12. Between the base 10 and the bridge 12 yis pivoted a key lever 14. In the example here illustrated, this lever is intended to move in the horizontal plane. The key lever 14'is tensioned in onel direction by the spring 16 which likewise may serve as an electrical connection to the key lever 14 and is connected by thev line 18 to the binding post 20. Movement of the key lever 14 under tension of the spring 16 is regulated by the adjusting screw 22 which passes through a post 24. It is to be noted that this screw is simply for mechanical ad? justment and is not in the electrical circuit.;

A post 26 carries an adjustable Contact screw 28 adapted to make electrical contact with the contact point 30 carried by the key lever 14. The key lever 14 likewise-carries an adjustable Contact screw 32 adapted to make electrical contact with contact point 34 carried by the spring key arm 36 which is mounted in a post 38. Spring keyarm 36 carries a key 40 and the key lever 14 carries a key 42. The spring key arm 36 is tensioned away from the key; lever 14 and its movement is limited by the mechanical adjusting screw 44 mounted in post 46.

The key lever 14 carries a vibrating spring 48 to which is connected bar 50 carrying a weight 52, the position of which maybe ladjusted by the thumb screw 54. At the end 'of thebar 50 is the adjustable.,` mechanical contact screw 56 adapted to strike'against thev insulated member 4Spring 60 is mounted in a post, 62 and nor.-V mally contacts `with the adjustable contact screw 64 mounted inpost66, which isiconl nected to the binding post 68. It is toV be noted that the post 26 is connected with `the post 62 by the wire Y70 and that post 38 is connected to the wire 7 0 by wire 72.

If the operator presses key 42 against the tension of spring 16, contact point 30 will strike against screw28, thus closing a circuit through the line. lThis circuit passesk from binding post 20 through wire 18, spring 16, key lever 14, contact point 30, screw 28, post 26, wire 70, post 62, spring 60, screw 64, post 66, and binding post 68. I-Iowever, if the key 42 is pressed over sharply, immediately after contact point 30 touches screw 28, screw 56 will strike the insulated member 58, breaking the contact between spring 60 and screw 64 so that a dot will be transmitted. If the key 42 is now held in this position, bar carrying screw 56 will vibrate, intermittently'breakingl the contacts between spring and screw 64 for brief intervals of time and allowing them to remain in contact for longer periods of time, thus transmitting a series ofdashes.' If the key 42 is released just as the contact between the spring v60 and screw 64 is made, a dot will result. Thus byV operation of key 42 a dot is first transmitted, then one or more dashes, and the nal indication may be either a dot or a dash. Undue.y

PATENT; .o1-"Fics y 58 carried 'by spring 60, ff

vibration of bar 50 may be limited by the i adjustable screw 74. Key 40 is used when a transmitting a series lof. dashes. As before,

2 .'i' L Y 1,759,584

the operator may cause the final indication to Vbe either a dash or a dot.V Y l ,It is to be understood that the apparatus here described Vis given by Way of illustration only and that the same may be modified in many particulars Without departing from the spirit of my invention.v

WhatI'elaimis: j Y 1. In a telegraphic transmitter of theV vi'- bratory type a pivoted key arm, a vibratoryV member connected therewith, contacts vvheref by movement of thekey arm Will close a'oir-V cuit independent of movementof the-vibra-V tory member andth'ereuponcause such vibratory member to operate, and means whereby movementrof. such vibratory member may j break such Circuit.V Y

. Y 2; A combination. as speeied in ClaimV il.,V

' whichV further includes a second key arm adapted to close Said circuitrp'rior tomove- Y mentof said first keyjarm and thereafterV to i move said lirst key'arm to initiate the movement of said vibratory member.

Y. CHARLESFREDERICK Mormon 

